Cotton is also biodegradable so no matter how much impact my cotton bag has in production, the hundreds of plastic bags I've not used are not sitting in a landfill for the next few thousand years becoming smaller but remaining plastic.
I'm OK with that until someone shows me a decent scientific reason why it's bad.
Woolworth’s actually gives you canvas bags, and I brought one back with me to use as a reusable shopping bag.
Those are about as bad as you can get for the planet. Manufacturing that much canvas is terrible for the environment.
The point is that you wouldn't need to make as many canvas bags as continuously re-using plastic bags, and one can keep re-growing cotton/paper, which also provides sustainable jobs, though it probably pays worse than working in the average chemical plant.
It would depend on the type of equipment and efficiency of the production used to make the canvas bags, as well as the distance to bring them from production to the market. If the canvas bags are made in China, but the plastic bags are made in Hackensack, then (assuming all production efficiency being somehow equal), the waste emissions alone for the trans-Pacific trip eat up a lot the environmental benefits in the near-term.* That's a bit to look up on an individual basis, but I think it's a matter of whether the other methods produce less environment damage by having a byproduct that doesn't hang around in the ecosystem for 50-500 years. I do admit that we keep personally and re-use those disposable bags several times, since they're quite useful for garbage collection, doggie waste, padding, travel laundry, et cetera. And due to travel, I have to stash a few reusable bags when I go places which do not offer them (it's also easier to lift and carry 2-3 bags by those handles, than 5-6 plastic ones, especially up a few flights of stairs).
Efficiency is why we can take a good look at an electric cars versus gas-powered vehicles because a power plant provides roughly 45-70% efficiency versus the average internal combustion engine, which is rated at 18-25% efficiency of fuel to motility, since a lot more heat and other spent-fuel byproducts are wasted.
* for example, hauling grand prix cars halfway around the globe on a cargo jet emits more CO
2 than all 20 racing cars during an entire race meeting (shhhh...)